If $A$ is any set, then
$A \cup A' = \phi $
$A \cup A' = U$
$A \cap A' = U$
None of these
Taking the set of natural numbers as the universal set, write down the complements of the following sets:
$\{ x:x\, \ge \,7\} $
Let $\mathrm{U}$ be universal set of all the students of Class $\mathrm{XI}$ of a coeducational school and $\mathrm{A}$ be the set of all girls in Class $\mathrm{XI}$. Find $\mathrm{A}'.$
Let $n(U) = 700,\,n(A) = 200,\,n(B) = 300$ and $n(A \cap B) = 100,$ then $n({A^c} \cap {B^c}) = $
Draw appropriate Venn diagram for each of the following:
$(A \cup B)^{\prime}$
If $U=\{a, b, c, d, e, f, g, h\},$ find the complements of the following sets:
$B=\{d, e, f, g\}$